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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?iso-8859-1?Q?q6Ep9jJXduHnm4aWdeyFkll2MWx7N8gY0zUgNs3Mkv1l2cqaukBwrbcgSD?= =?iso-8859-1?Q?ILTBpaQk7q9KjJm1TP/IlhEw50oTMMY5A4estjExKqYs+xx5YtnbWve0Vy?= =?iso-8859-1?Q?i6D13Ewj2ELptNqy83HugcHio9LcPyvgSG/c3SYFtxvIzOItIRi1S+tfpW?= =?iso-8859-1?Q?0msz0k/h6cvB8yns5OY4F9jpsK/9mOymNPFCTAmwQXthfBbwEg6wGvokhU?= =?iso-8859-1?Q?md0wMIFvsXoCTrMaQ7VoB0XPrV4ykvX7OP+7RkwEnavHb0VAiXUbMrSmYe?= =?iso-8859-1?Q?fXpq8yknmbXHAYISmFt1FAONfnzvkXS4B26ffLLlRV6gk0Hf+2PXbBQGC5?= =?iso-8859-1?Q?KH5AJ63skd4Bpbi86U5xGFe8W3EBWPsqagDkQsWlHEevYqVTEXKx0jvqK3?= =?iso-8859-1?Q?jws7H0ONplSV/OcwF1DM2EvnUrqFWIKWQuiERaPFlvS+/zbvW996jHSpWo?= =?iso-8859-1?Q?9GnoyowQYSkkrSd6NSnHd1QIHdGC7lFXmg/O86EGtnxYwwFCWV5LBT688/?= =?iso-8859-1?Q?y1359FV8PziRhd2qrARaatRGSBkpJw3VCC+jnTTQKVE7FgujHP083HOKrH?= =?iso-8859-1?Q?Is+GdFnlP/mqIKpebTCJztlfQ5HFvqXlHhmNrFDfv7bR48KfeO7IjV9w0p?= =?iso-8859-1?Q?urMH+AB6cYO4NOljwNGTwQEidDTOmk+doPZjXY5nF43Ht1xomQViMhrAK7?= =?iso-8859-1?Q?EJ1tY8aOUGF5aeJMhgG8uRTXNXAyCDDbBsgP8UxJd/cdru+CEAhorU7yzK?= =?iso-8859-1?Q?1l0RsqDhoo3V06+tMnxt81kY9OgMLqe/vLADEFgM+ezDVU+ADJ35/pzPuV?= =?iso-8859-1?Q?wqf6xbk26/0dO2Y0llI3dkgUIFrau5lTRaRPvxvpLM7WLiUTediYwjGbpM?= =?iso-8859-1?Q?s8HXP7bRW+HhKjqR3wmg6z+6wBZp6sf8qjx+VK1/mgD2GgvVAsFouGxiNl?= =?iso-8859-1?Q?hSyTTM/cb8K0OOixMKT9YSzX8p1gzzzMOIG0RWWnkNDsA23aKboGQubYgv?= =?iso-8859-1?Q?CUr3gq7uUTY1+6SJnA51j6CBXtvGtHuIxPoMnH2SWWpRaCFyx4UxZRvWoa?= =?iso-8859-1?Q?A1gJ35jig7JnQtAbfAhTm3QC3BkiCpUmqckdxWoJjT4Z6dVXE5aUtbbGbj?= =?iso-8859-1?Q?jsEV/nVwqnxlSdJmmlcZSeiyPDfNBYy2JbXWOONmIV+90rcudJX8sz/F7g?= =?iso-8859-1?Q?ZwbbmP2ol6MBj6s+hErlsVUhLGDV+chLPZHCT6JvVLNzzV2rjsXB2g00MI?= =?iso-8859-1?Q?fLLENFOlbd+vszoeatRbq6jEi+kAAcajZfGvUHrVIdRJICvkxeP9SBaU4Q?= =?iso-8859-1?Q?soYdxmItp9gZbadS8B+bLfVEGEK1UB8JulnjNX8ZxbeUTsYH9ZW1v3fhoL?= =?iso-8859-1?Q?w6L7iF7YMR?= X-OriginatorOrg: corigine.com X-MS-Exchange-CrossTenant-Network-Message-Id: 36fea254-c24a-4cc7-a224-08d98425296c X-MS-Exchange-CrossTenant-AuthSource: DM6PR13MB4431.namprd13.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Sep 2021 15:15:39.4541 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: fe128f2c-073b-4c20-818e-7246a585940c X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: z3mG/pxM/LJc1saTlc0VreUSo+g5p/BpfKz5OU9BroLx6mPHO8BcS8pBmkKB0zxzsyurwLyDpSGFRCD0whJYfPCaTn6u7hndIbqRrHBI5e0= X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM5PR13MB1450 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2021-09-30 07:59:59 -0700, Jakub Kicinski wrote: > On Thu, 30 Sep 2021 16:46:34 +0200 Niklas Söderlund wrote: > > When the MTU is changed after the program is offloaded the check in > > nfp_bpf_check_mtu() is consulted and as it checks the MTU differently > > and fails the change. Maybe we should align this the other way around > > and update the check in nfp_bpf_check_mtu() to match the one in > > nfp_net_bpf_load()? > > That sounds reasonable. Although I don't remember how reliable the > max_pkt_offset logic is in practice (whether it's actually capable > of finding the max offset for realistic programs or it's mostly going > to be set to MAX). > > > On a side note the check in nfp_net_bpf_load() allows for BPF programs > > to be offloaded that do access data beyond the CMT size limit provided > > the MTU is set below the CMT threshold value. > > Right, because of variable length offsets verifier will not be able to > estimate max_pkt_offset. Thanks, this made the design click for me. > > > There should be no real harm in this as the verifier forces bounds > > check so with a MTU small enough it should never happen. But maybe we > > should add a check for this too to prevent such a program to be > > loaded in the first place. -- Regards, Niklas Söderlund